Track installation for train-control systems



Jan. 3, 1928.

T. E. CLARK ET AL TRACK INSTALLATION FOR TRAIN CONTROL SYSTEMS VE TORs F 6' ATTORNEY Filed Feb. 25. 1926 L ME a! Patented Glen. 3, 1923..

UNITED STATES 1,655,221 PATENT, OFFICE.

THOIiLFLS E. CLARK AND JAIVIES E. CLARK, OF DETRQIT, MICHIGAN, ASSIGNORS TO CONTINUOUS TRAIN CONTRQL CORPUS BATION OF MICl-IEGAN.

ATT I, QF DETROIT, MICHIGAN, A CORPO- TRACK INSTALLATION FOR TRAIN-CONTROL SYSTEMS.

Application filed February as, 1926. Serial No. 90,513.

This invention relates to the control of railway trains by means of high frequency currents ropagated in the rails oi tracks which are divided into blOClIS, a current propagatin device being connected to the rails oi each bloclr, preferably at the exit end thereof, and each proj'iagating installa tion embodying means nfluenced rent in the rails of the block to which it connected, and its objectto provide it ourrentpropagating system oi s character which will insure a practical, uniform electric condition throughout the energized block; V

This invention is of the actor as that forth in our prior application Serial Number 74,983, filed December 12, 1925, and the same locomotive installa tion is again employed, the dilierence hetween the present invention and that of our prior application consisting principally in the use of a single wayside conductor and in the type of combined transformers and inductances between said single conductor and the two rails of the block supplied with current by saic single conductor.

In the accompanying drawings, Fig. 1 is a diagram of track and locomotive installa tions embodying the present invention, and it is understood that the direction or" travel is from righ' to left. Fig. 2 is a view of a transformer.

Similar reference parts in both views.

The rails 1 and 2 blocks A and B by means of .insulatious o in the usual manner and a track installation connected to the exit end of block A. The track and locomotive installations embody relays whose ii-matures are indicated by small letters which will. he used with the designating characters of the relays.

Alternating current is supplied to the two line wires 5 and 6 from any current source, and each track installation embodies a wire 7, over which current normally flows over primary winding 8 of the main transformer, wire 9, armature c 01 a high -resistance polarneutral relay 10, .vire 12, armature a of relay 13 and wire 14. Each relay is controlled by the current in the track rails of the block ahead and has three conditions, positively energized, negatively energized and Clo-energized. When it is either posi- 1 general I L See characters refer to like are shown divided into tively or negatively energized, it attracts its armatures a, Z) and 0 and thus closes the circuit to the primary winding 8, but when it is deenergized, which occurs when its block of track is occupied, the circuit to the pri mary winding is opened and the adjacent. tracl installation for the next block in the rear is inoperative.

The vacuum tubes 15 and 16 are the generators of the control currents and their filaments receive current from the portion 17 of the secondary winding of the main transformer, the current passing over wires 18 and 19, variable resistance 20 and wire 21 to the filament of tube 15 and back over wires 23 and 2 1 to winding 17. Current also pa ses over wire 18, adjustable resistance 25 and wire 26 to the filament of tube 16 and back over wire 24. I

The secondary winding of the main transformer for the plate current of tube 15 consists of theparts 17 and 27, while that for the tube 16 consists of the parts 1'7, 27 and. 28. The plate circuit of the tube 15 during the positive portion of the cycle of the current in wires 5 and 6, is over wire 23, coils 17 and 27, wire 32, coil 31 and wire 30 to the plate, while the circuit during the negative portion is over the wire 30, coil 31, wire 32, condenser 38, wires 18 and 19, resistance 20 and wire 21. These plate circuits carry a pulsating current of high frequency and cause a pulsating charge in the grid circuit of this tube 15, said rid circuit consisting of the wire all, inductance coil 42, wire L3, extending therefrom to the grid leak ll and condenser 45, and wire as.

The coil being the secondary of a transformer of which the coil 31 is the primary, a pulsating charge is impressed upon. the grid circuitand ne 'ative potential is charged on and discharged from the grid of tube 15, the condenser and grid leak 44. preventing positive potential in the grid. This charge and discharge is probably both the cause and etlect of the pulsations in the plate circuit and coil 31. The rate of vibrations and the wave lengths of the currents are controlled by the adjustable condenser 17 which shunts the coil 31.

The positive half of the plate current of tube 16 flows from coils 27 and 28, over wire 36, inductance coil 35 and wire 34, the negative half being blocked by the rectifying action of the tube, and the condensers 38 and 39 serving as low resistance paths for the radio-frequency oscillations toby-pass the windings and 28. The plate current, therefore, never flows in the opposite dircce tion through the coils 27 and 28 of the main transformer. The adjustable condenser 37 tunes the plate circuit of tube 16 into resonance with the plate circuitof the other tube. The grid of tube 16 is controlled by the inductance coil 31 of tube 15 acting .on the inductance coil 18 which con nects to the wire 2st by the wire 49 and to the gridleak 50 and condenser 51 by the wire 52. The wire 53 connects the grid of tube 16 ,to its leak and condenser. As the charge in this grid pulsates in unison with the charge in the grid of and with the current in the plate circuit of tube 15, the plate current of tube 16 also pulsates insuch unison.

' If the tube 15 alone were used and the wires 49 and 52 were connected directly to the rails at their exit ends, which, together with these wires would constitute a track circuit the train moving from the entrance end of theblock toward the exit end would shorten this track circuit and thus change lengths of the plate circuits of tube 15 through the reaction between the inductance coils 48 and 31 which are inductively con nected. But the frequency of the pulsations of the plate Circuit of output tube 16 is controlled by the grid circuit which includes the coil48 which circuit always pulsates in unison with the plate circuit of tube 15 which is unaffected by any change in the track circuit. The rate of vibrations and wave lengths are therefore controlled by the tube 15 and its circuits. of very much less capacity than the tube 16.

In the operations of train control systems employing the track installations above described. great ditiiculties were met with because the current in the rails dissipated from the input end of the block. which is usually the exit end, toward the entrance end and the mechanism which embodies iheprescnt inventionhas been devised to overcome these difliculties and to insure a substantially constant current of sufficient strength throughout the block. Much of the success of the present invention arose from the proper in.- stallation of the transformer shown in Fig. 2,. which is admirably adapted for currents of radio frequency.

The transformer is in the form of a rectangle comprising sides or cores and ends and is built up of thin sheets of steel coated with aninsulating varnish, preferably by dipping, and united by taping, each sheet con'iprising a body 85 forming part of a core and parallel arms 86 ext-ending at right angles toward the other core and lying flat between similar arms, extending from the This tube may be.

amperage.

The fixed output inductance 5T co-acts with the inductance coil 35 of the plate (11'- cuit of the tube 16, and this output coil is a portion of an oscillating circuit which is asfollows: from the coil 57 over condenser 89, wires and 91 and primary winding 88. Only a part of the current passes over the wire 91, and the remaining portion of the current passes over the wire 55, over wires 92, windings 88 ofthe other transformers, wires 93, rail 1, wires 82, '93 and 94 to the coil 57. The circuit of the secondary winding 90 of the transformer nearest the station is from the winding over the adjustable resistance 95, condenser 96, wires 97 and 81 to rail 2, then over leading axle Tot a t "air! to rail 1, wires 82,93 and 9 1 to the winding 90. The circuits of the other secondary windings are the same except that the wires 93 and 97 are connected directly to the rails. The condensers 96 prevent the passage of signal and other currents which may be flowing in the rails to the transformers.

The number of these transformers and con nections may be varied as desired to meet local conditions of ballast and dissipation of current by the rails.'

In the drawing, we assume that .the rack in advance of block B is unoccupied for three or more blocks, and the high resistance relay 10, is therefore energized, holding up its arinatures. The control current of the track battery of bloclrB (not shown) passes rearwardly along the rail B1, wire 68, relay 10, wire 67 and rail 2 back to battery. This so energizes the relay that itsarinaturcs (Z and c are swung clockwise and an additional condenser 69 is shunted into the plate circuit of tube 15 by this armature (Z bridging the wires 70 and T1 and an additional condenser 73 is shunted intothe plate circuit of tube 16 by the arn'iaturc c bridging the wires 74:, and 75. This lengthens the waves in these plate circuits and results in" the long waves being propagated in the track rails.

The control current for block A is derived from the battery66 (Fig. 1), and flows over wire 77, resistance 78, armature 10, wire 79, choke coil and wire81 to rail 2 and to high resistance relay at the entrance end of block A, thence back over rail 1, wire 82. choke coil 83, low resistance relay 13, wire 8 1, armature 10. and wire 85 to the battery. As relays 10 have high resistance, low resistancerelay 13 of ablock is not sufficiently energized to attract its armature until a train short circuits the rails and cuts. Out relay 10,

stantially when relay 13 gets sutlicient current to attract its armature and closes the circuit to the main transformer.

The train control installation of a block, therefore, is inoperative unless the block is occupied, at which time the relay 10 at the entrance end of the block is de-energized The operation of the track installation is fully set forth in our above named application.

These track installations propagate subuniform electro-magne ic waves in the rails throughout the lengths of the blocks. the lengths of the waves or their absence being automatically detern'iined by the occupancy of the track ahead, and such propagation taking place only in occupied blocks, thus saving current and insuring maximum life of the tubes. The track battery 66 controls the lengths of the waves of the current output of the next stat-ion in the rear. lVhen block B is occupied, relay-10 at its entrance end is de-energized and its an matures drop causing negative current to flow to rail 1. lVhen block 13 is unoccupied, relay 10 is energized and positive current flows to rail 1 and to relay 10 of the next station in the rear. Positive current causes polar armatures (Z and e to swing clockwise but negative current causes counter-clockwise movement. As stated before, this clockwise movement causes condensers 69 and 73 to be shunted into the plate circuits and in the propagation of longer or clear wave lengths in the track rails. 1

The locomotive installation embodies two collector coils and101, which connect to the. grids of the vacuum tubes 102 and 103 as follows: from the coil 100 overwire 104, condenser 105, grid leak 106, and wire 107 back to the coil, an adjustable condenser 112 being mounted between the wires 104 and 107 to tune this circuit to resonance with current of one wave length in the track. The grid circuit from coil 101 is over wire 106, condenser 109, grid leak 110 and wire 111 back to the coil 101, the adjustable condenser 112 being used to tune this circuit to resonance with the current of the other wave length flowing in the track rails under certain tratfic conditions.

The current for the filaments of these tubes passes from the two-voltage generator 113 over wires 114, 115 and 107 to the filament of tube 102, over wire 116 to the filament of tube 103, and wire 111, adjustable resistance 117 and wires 118 and 119 back to the generator.

' lVhen either of the collector coils 100-l01 picks up current, a negative potential charge accumulates on the grid element to which the coil is connected. This obstructs the normal action of the tube and few electrons pass to the plate from the filament. lVhen neither tube receives current, high voltage current flows from the generator 113 over wires 119 and 118, resistance 117 and wire 111 to filament of tube 103 and wire 116 to filament of tube 102. Plate current flows from the plates of both tubes to the windings 1.20 and 121 of a polar neutral relay over the wires 122 and 123, and thence over the wires 124 and 125 to the generator. As the two coils and 121 neutralize each other, the neutral arinatures a and Z) are not attracted and the current flows over wire 114 to red lamp R- and over wire 124, armature 7) and wire to show that there is no current in the rails.

Current picked up by coil 100 causes the winding 120 tobe ale-energized and winding 121 to swing armature o counter-clockwise to complete the circuit from wire 114, over yellow lamp Y, wire 126, armature 0, wire 127, and armature Z), while current picked up by collector coil 101 causes coil 121 to be d energized and the armature 0 to swing to the position shown in Fig. 1, the current flowing from wire 114 over green lamp G, wire 128 and armature 0.

But if both coils 120 and 121 are energized by reason of no current in the rails, or if the installation becomes inoperative, the circuit over wire 1.27 is opened and the circuit to the red lamp is closed. At the me time, the circuit to the electro-magnetic valve 130, including wires 114 and 131, armature a, and wire 132, is opened. This valve is well known and embodies a magnet or solenoid by wl "ch it is kept closed so long as it is energized, but when tie-energized, this valve releases the pressure in the train line pipe and causes the brakes to be applied.

When, therefore, either coil 100101 picks up current, one of the coils 120-121 attracts its armatures and holds the circuit to the el-ectro-pneumatic valve 130 closed, but if neither receives current, the brakes are applied. The three signal lamps indicate the condition of the track ahead, and referring to the description of the track installations, clear conditions in the occupied block result in a green lamp, caution conditions result in a yellow lamp, and rjlangefi conditions in a red lamp burning in the cab. Danger conditions in the occupied block always cause the brakes to be applied, but clear and caution condi tions do not. i

The details of construction, the arrange ments of the circuits and the ratios of the wave lengths may all be changed by those skilled in the art without departing from the spiritof our invention as set forth in the following claims.

e claim 1. In a train control system, in combination with the rails, a coil carrying radi0-frequ'ency current, means connected to the rails to vary the frequency of said current, an output circuit embodying a second coil co-acting with said first named coil, a series of transformers of high-frequency current embodying primary and secondary windings, a conductor connecting all the primary windings to said output coil, conductors connecting each winding one of the rails and one end of the output coil to the same rail, and independent conductors connecting one end of each secondary winding to the other rail.

In a train control system, in combination with the rails, a coil carrying radio-frequency current, means connected to the rails to vary the frequency of said current, an output circuit enil'iod'ying a second coil coacting with said first named coil, a series of transformers of high-frequency current embodying primary and secondary windings, a conductor connecting all the primary windings'to said output coil, conductors connecting each winding to one of the rails and one end of the output coil to the same rail, and independent conductors connecting one end of each secondary winding to the other rail, one of said conductors for each secondary winding embodying an adjustable resistance.

In a train control system, in combination with the rails, an oscillating circuit emloodying a coil carrying high-frequency currents of varying amplitudes according to the occupancy ofthe rails in advance, an output circuit embodying a coil reacting to the current in said oscillating circuit, a se lies of transformers connected to said output circuit and embodying primary coils and secondary windings, and connectors between each secondary winding and said rails.

l. In a train control system, in combina tion with the rails, an oscillating circuit embodying a coil carrying high-frequency currents of varying amplitudes according to the occupancy of the rails in advance, an output circuit embodying a coil reacting to the current in said oscillating circuit, aseries of transformers connected to said. out put circuit and embodying primary coils and secondary windings, and connectors between each secondary winding and said rails, said secondary windings having fewer turns and being of heavier wire than the primary windings.

5. In a train control system, in combina tion with the rails, an oscillating circuit eni-' bodying a coil carrying high-frequency currents of varying amplitudes according to the occupancy of the rails in advance, an output circuit embodying a coil reacting to the current in said oscillating circuit, a se ries of transformers connected to said output circuit and embodying primary coils and secondary windings, and connectors between each secondary winding and said rails, said transformers having cores in pairs, one for each winding, and formed or sheet metal with arms at both ends extending toward the other core and lapping the arms extending therefrom.

-6. Ina train control systennin combination with the rails, a coil carrying high-frequency current, an output circuit embodying asecond coil co acting with said, first named coil, a scriesof transformers of high-frequency current en'ibodying primary and secondary windings, a conductor connecting ah the primary windings to said output coil, a separate conductor connecting looth windings of each transformer to one of the rails and one end of theoutput coil to the same rail, independent conductors connecting one end of each secondary winding to the other rail, and means for propa ating high freq'uency current of predetermined wave length in said first named coil.

7. In a train control'system, in combina tion with the rails, a coil carrying high-frequency current, an output circuit embodyin a second coil co-acting with said first named coil, a series of transformers of high-frequency current embodying prin'iary and secondary windings, a conductor connecting all the primary windings to said output coil, a separate conductor connecting both windings of each transformer to one of the rails and one end of the'output coil to the same rail, independent conductors connecting one end of each secondary winding to the other rail, an electron tube connected to said first 1 named coil to propagate high-frequency current in said rails, and means to control the lengths of the waves of said current.

8. In a train control system, in combination with the two rails, means for generating radio-frequency current embodying an output coil, a conductor connecting one end of said coil to one of the rails, a line conductor extending along the track, a series of transformers and conductors connecting the primary windings of said transformers to said line conductor and to the other rail, and conductors connecting the ends of the secondary windings of said transformers to both of said rails, said secondary windings being tuned to deliver current of predetermined frequency of oscillation.

THOMAS E. CLARK. JAMES E. CLARK. 

